1. Technical Field
The present invention relates to a communication device which is connected to a network access device constituting a network and is capable of communicating through the network.
2. Related Art
Communication through a network can be performed by connecting a communication device such as a PC (Personal Computer) and a printer to a network access device (switch, bridge, router, etc.) on the network.
In recent years, power saving is demanded for the communication device. For example, as a technique for power savings in the communication device, a technique of lowering the communication speed (link speed) to the network access device to reduce power consumption is known (e.g., see JP-4275169).
As a protocol applied to the network, STP (Spanning Tree Protocol), which is a protocol for allowing a LAN (Local Area Network) including a loop to be logically operable as a tree type network, is known.
According to the technique of Japanese Patent No. 4,275,169, it is possible to reduce power consumption in the communication device by lowering the link speed (communication speed) to the network access device.
However, according to the kind of STP applied to the network, when the link speed between the communication device and the network access device is changed, there is a case where a process of learning the structure of a spanning tree is performed according to STP, and a state where communication on the network is blocked occurs, for example, for 30 seconds.
When such blocking of communication occurs, communication is not performed for the communication device connected to the network, a communication error occurs, and the process may not be appropriately performed.